(57) This procedure refers to the incorporation of granules of cork or similar substances
into polyurethane products. The polyurethane components and the cork (or similar)
granules are introduced simultaneously into a suitable mixing chamber (26), the granules
being suitably dosed by variable speed programmable screw conveyors (or otherwise,
for example pneumatic feeds, mechanical pistons, etc.). The conglomerate as above
is introduced, while still in the early stages of reaction, into fixed or moveable
moulds (40) or dies by gravity (with the mould open), or by injection (with the mould
closed), and completes its reaction there, forming the product in times which vary
according to the characteristics of the mixture used and the shape of the article
produced. The moulds or dies are preferably kept at a temperature of about 50°C, though
this is not critical since this factor also varies widely according to the polyurethanes
used and the pieces being produced.
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